Hematopoietic progenitor kinase 1 (HPK1/MAP4K1) represents a high interest target for the treatment of cancer through an immune-mediated mechanism. Herein we present highlights of the drug discovery campaign within the lactam/azalactam series of inhibitors that yielded a small molecule (21, PF-07265028), which was advanced to a phase 1 clinical trial (NCT05233436). Key components of the discovery effort included optimization of potency through mitigation of ligand strain as guided by the use of cocrystal structures, mitigation of ADME liabilities (plasma instability and fraction metabolism by CYP2D6), and optimization of kinase selectivity, particularly over immune-modulating kinases with high homology to HPK1. Structure-based drug design via leveraging cocrystal structures and lipophilic efficiency analysis proved to be valuable tools that ultimately enabled the delivery of a clinical-quality small molecule inhibitor of HPK1.

Ibuzatrelvir (1) is a second-generation, orally bioavailable, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) main protease inhibitor clinical candidate. Herein, we report the implementation of an in silico and high-throughput experimentation strategy leading to the identification of a rapid, efficient, and sustainable route to trans-4-trifluoromethyl-l-proline (2), a key building block for ibuzatrelvir. This novel synthetic route features a key stereochemical editing step to enable an efficient and scalable protocol that operates under mild conditions with high stereoselectivity, providing effective access to more than 235 kg of trans-4-trifluoromethyl-l-proline 2 in a five-step synthetic sequence from readily available starting materials.

Herein, we report the optimization of the first process chemistry route for pilot-plant-scale manufacture of PF07059013 (1), a noncovalent modulator of hemoglobin for the treatment of sickle cell disease. Five areas of improvement are discussed in detail, namely, an alternative synthetic sequence to install the pyridone functionality before benzylic ether formation, a shorter and safer route to quinoline fragment 9, a tosyl-swap strategy to avoid isolation of a thermally unstable tosylate intermediate, Pd-catalyzed C-O coupling with low catalyst loading and efficient Pd removal, and improved final isolation of the API freebase. The new route was executed in our pilot plant facility to deliver 76 kg of API.

Auristatins, synthetic analogues of the antineoplastic natural product Dolastatin 10, are ultrapotent cytotoxic microtubule inhibitors that are clinically used as payloads in antibody-drug conjugates (ADCs). The design and synthesis of several new auristatin analogues with N-terminal modifications that include amino acids with α,α-disubstituted carbon atoms are described, including the discovery of our lead auristatin, PF-06380101. This modification of the peptide structure is unprecedented and led to analogues with excellent potencies in tumor cell proliferation assays and differential ADME properties when compared to other synthetic auristatin analogues that are used in the preparation of ADCs. In addition, auristatin cocrystal structures with tubulin are being presented that allow for the detailed examination of their binding modes. A surprising finding is that all analyzed analogues have a cis-configuration at the Val-Dil amide bond in their functionally relevant tubulin bound state, whereas in solution this bond is exclusively in the trans-configuration. This remarkable observation shines light onto the preferred binding mode of auristatins and serves as a valuable tool for structure-based drug design.

Glucokinase is a key regulator of glucose homeostasis, and small molecule allosteric activators of this enzyme represent a promising opportunity for the treatment of type 2 diabetes. Systemically acting glucokinase activators (liver and pancreas) have been reported to be efficacious but in many cases present hypoglycaemia risk due to activation of the enzyme at low glucose levels in the pancreas, leading to inappropriately excessive insulin secretion. It was therefore postulated that a liver selective activator may offer effective glycemic control with reduced hypoglycemia risk. Herein, we report structure-activity studies on a carboxylic acid containing series of glucokinase activators with preferential activity in hepatocytes versus pancreatic β-cells. These activators were designed to have low passive permeability thereby minimizing distribution into extrahepatic tissues; concurrently, they were also optimized as substrates for active liver uptake via members of the organic anion transporting polypeptide (OATP) family. These studies lead to the identification of 19 as a potent glucokinase activator with a greater than 50-fold liver-to-pancreas ratio of tissue distribution in rodent and non-rodent species. In preclinical diabetic animals, 19 was found to robustly lower fasting and postprandial glucose with no hypoglycemia, leading to its selection as a clinical development candidate for treating type 2 diabetes.

Novel siderophore-linked monobactams with in vitro and in vivo anti-microbial activity against MDR Gram-negative pathogens are described.

Glucokinase is a key regulator of glucose homeostasis and small molecule activators of this enzyme represent a promising opportunity for the treatment of Type 2 diabetes. Several glucokinase activators have advanced to clinical studies and demonstrated promising efficacy; however, many of these early candidates also revealed hypoglycemia as a key risk. In an effort to mitigate this hypoglycemia risk while maintaining the promising efficacy of this mechanism, we have investigated a series of substituted 2-methylbenzofurans as "partial activators" of the glucokinase enzyme leading to the identification of N,N-dimethyl-5-(2-methyl-6-((5-methylpyrazin-2-yl)-carbamoyl)benzofuran-4-yloxy)pyrimidine-2-carboxamide as an early development candidate.